Selasa, 6 November 2012

A network can consist of two computer
connected together on a desk or it can consist of many LOCAL AREA NETWORKS(LAN) conected together to form a WIDE AREA NETWORK(WAN).all types of
networking require special networking software to allow different computers to
communicate will each other.

EXAMPLE OF AREA NETWORK TYPE:

LAN: local area network

WAN: wide area network

MAN: metropolitan area network

WLAN: wireless local area network

SAN: storage area network,system area
network.

CAN: campus area network

LAN(local
area network)

LAN
connects networking devices with in
short spam of area ex:small office,home,internet cafe. Etc,LAN uses TCP/IP network protokol for communication
between computers.it is often but not always implemented as a single IP subnet.

WAN(wide
area network)

WAN cover large distance for communication
between computer.the internet itself is the biggest example of wide area
network.WAN is distributted of geographically y LANs.a network connecting
device router connects LANs to WANs.WAN
used network protocol like ATM,X.25,and frame relay for long distance
connectivity.

MAN(METROPOLITAN AREA NETWORK)

MAN importance for some government bodies and
organization on larger scale. MAN falls in middle of LAN and WAN ,it cover
large span of physical area LAN but smaller than WAN,such as a city.

WLAN(wireless local area network)

WLAN
based on wireless network technology mostly referred as wi-fi unlike LAN,in
WLAN no wires are used,but radio signal are the medium for communication.wireless
network card are required to be installed in the system for accessing any
wireless network around.mostly wireless card connect to wireless routers for communication among computer or accessing WAN,internet.

SAN(storage area network)

SAN technology is used for data storage and it has no use for most
of the organization but data oriented organization.STORAGE AREA NETWORK
connects server to data storage devices
by using fiber channel technology.

SAN(system area network)

SYSTEM AREA NETWORK are also known as cluster
area network and it connect high performance computers with high speed
connections in cluster configuration.

CAN(campus area network)

Networking spanning with multiple LANs but
smaller than a metropolitan area network(MAN)This kind of network mostly used in relatively large universities
or local business offices and buildings.

NETWORK TOPOLOGY

Network topology refers to the way in which
the conections within the network are made.there are two types of topology:

-physical
topologies

-logical
topologies

PHYSICAL TOPOLOGIES

The physical topology is how the computer and
peripheral are connected and how the cable is run between them,in other word
the way the networks look.

THE
THREE COMMON PHYSICAL TOPOLOGIES FOR LOCAL AREA NETWORK ARE:

-STAR

-RING

-BUS

OTHER
LESS COMMON PHYSICAL TOPOLOGIES INCLUDE:

-TREE

-MESH

LOGICAL TOPOLOGIES

The logical topologies describes the way in
which a network transmit informations from one node to the next node.

THE
MOST COMMON LOGICAL TOPOLOGIES ARE:

-BUS

-RING

STAR TOPOLOGY

In a star network ,each terminal is
directly connected to a central hub.each
connection is independent of all other
connection.a twisted-pair cable is common for configuration,but coaxial or
fiber optic cable may also be used.

Advantages

-easy to install

-if one nodes fails,other nodes will not
effected

-data transfer between the central server and
the nodes is relatively low,therefore a low cost cable like twisted-pair cable can be used to
connect the nodes to the server.

Disadvantages

-if the hub fails then all nodes attached will
go down.

-requires more cable than most of the other
topologies.

-a central connecting device allows for a
single point of failure.

-more difficult than other topologies to
impliment.

RING TOPOLOGY

In this type of network each node is connected to the one on either
side of it so that they form a ring.data travel from one node to the next until
it reaches its destination.each node is responsible for capturing data
addressed to it or for transmitting the data to the next node by way of a
signal.coaxial and fiber optic cables are commonly used for this type of
network.twisted-pair cables provide a bit rate of up to 16 Mbps.

Advantages

-all nodes on the network have an equal chance
of transmitting data.

-cable fault are easy located,makin
troubleshooting easier.

-moderately easy to install

Disadvantages

-failure of one node will result in a shutdown
of all other nodes

-difficult to add or delete nodes because of
the physical layout

-signal may get lost

BUS TOPOLOGY

In a bus network all nodes on the network
share a common cable which is terminated at each end.transmission is passed
back and forth along the cable.as messages pass,each node checks the
destination address and accepts the messages if the adress matches the node
adress.

Advantages

-If one node crashes it will have no effect on
the rest of the network.

-does not use any specialized network
equipment.

-requires less cable than other topologies.

Disadvantages

-a fault on the cable will disable the whole network

-difficult to troubleshoot

-all system on the network connect to a single
backbone,a break in the cable will prevent all system from accessing the
network.

-require a network protocol to detect when two
nodes are transmitting at the same time.